Pressure is quoted in pounds per square inch (psi) in the United States and in bar or kilopascals almost everywhere else. Car manuals, bicycle pumps, compressors, pressure washers and scuba gear may list either one. This converter turns psi into bar and adds the kPa and atmosphere equivalents, plus the absolute pressure if your reading came from an ordinary gauge.
How to use the psi to bar converter
- Enter the pressure in pounds per square inch (psi).
- Read the result in bar, then kilopascals and standard atmospheres.
- If the number came from a tire or air-line gauge, the gauge to absolute row adds atmospheric pressure at sea level.
- Scroll down for a psi-to-bar chart and typical tire pressures in all three units.
PSI to bar formula
Both units have exact definitions. A bar is exactly 100,000 pascals. A psi is one pound-force (4.4482216152605 N) on one square inch (0.00064516 m²), which is 6,894.757293168 Pa. Dividing gives 0.06894757293168 bar per psi.
Worked example
Your car’s door placard says 35 psi and your European pump reads in bar.
35 × 0.0689476 = 2.41 bar.
In kilopascals: 2.41 bar × 100 = 241.3 kPa.
Absolute pressure inside the tire at sea level: 2.41 + 1.013 = 3.43 bar(a), or 49.7 psia.
A quick mental check: 35 ÷ 14.5 = 2.41. Dividing by 14.5 is accurate to about 0.03%, plenty for any tire gauge.
Typical tire pressures
| Use | psi | bar | kPa |
|---|---|---|---|
| Mountain bike, tubeless (low end) | 22 | 1.52 | 152 |
| Passenger car, common placard | 32 | 2.21 | 221 |
| Passenger car, upper common value | 36 | 2.48 | 248 |
| Light truck, load range E (max) | 80 | 5.52 | 552 |
| Road bike, typical | 90 | 6.21 | 621 |
| Road bike, high end | 120 | 8.27 | 827 |
Always use the pressure on your vehicle’s door-jamb placard or owner’s manual, not the maximum molded on the tire sidewall. The placard value balances grip, wear and load for that vehicle; the sidewall number is the tire’s limit.
Gauge vs. absolute pressure
- Gauge pressure (psig, barg) is measured relative to the surrounding air. Tires, compressors, hydraulic systems and household water use it.
- Absolute pressure (psia, bar(a)) is measured from a perfect vacuum. Weather, altitude, engine manifold sensors and gas-law calculations use it.
- Atmospheric pressure at sea level is 14.696 psi, 1.01325 bar or 101.325 kPa, and it falls with altitude — about 12.2 psi in Denver.
When a spec does not say which one it means, gauge pressure is the usual assumption for equipment, absolute for science.
Related conversions
| psi | bar | Context |
|---|---|---|
| 14.7 | 1.013 | One standard atmosphere |
| 50 | 3.45 | Typical home water pressure |
| 90 | 6.21 | Typical air-tool operating pressure |
| 3,000 | 206.8 | Typical aluminum scuba cylinder |
To convert the other way, use bar to psi. For pascals, mmHg, inches of water or any other pressure unit, use the full pressure converter, and to calculate pressure from force and area, try the pressure calculator.
Frequently asked questions
How many bar is 1 psi?
One psi is 0.0689476 bar. Put the other way, 1 bar is 14.5038 psi, so divide psi by 14.5 for a quick estimate.
What is 32 psi in bar?
2.21 bar (32 × 0.0689476 = 2.206). Many passenger cars specify 32 to 36 psi, which is about 2.2 to 2.5 bar.
Is tire pressure gauge or absolute pressure?
Gauge. A tire gauge reads pressure above the surrounding atmosphere, so a reading of 35 psi means about 49.7 psi absolute at sea level. Tire, compressor and plumbing figures are almost always gauge pressure (psig or barg).
Why does my tire pressure change in cold weather?
Gas pressure follows absolute temperature. A common rule of thumb is about 1 psi (0.07 bar) of loss for every 10 °F (5.6 °C) drop, which is why tire-pressure warning lights often come on during the first cold morning of autumn.